Golf club head

ABSTRACT

A golf club head is provided. The golf club head includes a face plate and a body. The face plate has an annular fastening portion with at least one fastening groove mounted therearound. The body has a clamping portion including at least one annular block and at least one annular stopper, so as to form an accommodation slot for accommodating the annular fastening portion. At least one flange is disposed on the top of the clamping portion. When the accommodation slot corresponds to the annular fastening portion, the face plate is squeezed towards the body, and the flange bears against the face plate and is squeezed and deformed to form a catching portion for engaging into the fastening groove, so that the face plate and the body are combined into a club head. The annular block bears against the annular fastening portion, so that the annular fastening portion and the accommodation slot are closely adhered to each other to prevent slits from being generated on the joint surface, and thus closely combining the face plate with the body as a whole.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a golf club head. More particularly, the present invention relates to a golf club head, which utilizes a flange and a groove to be squeezed with each other and to be deformed so as to form a close engagement relation.

2. Description of the Prior Art

Generally, in a golf club head, a body and a striking face plate are mostly combined through a titanium-pressing technique. At least one flange and at least one groove are correspondingly disposed on corresponding end surfaces of the body and the striking face plate respectively, and the flange and the groove are squeezed with each other to generate a deformation function, so as to closely match the club head with the striking face plate into a whole. However, in this method, if the shape and the position of the flange and the groove are poorly designed, both the flange and the striking face plate are easily deformed during squeezing, and as a result, the striking surface is restricted to a plane, which makes the light-weighting or weighting effect limited, and makes the elastic effect poor, and thus, the effective striking area is relatively small. Therefore, people skilled in the art combine the club head body with the striking face plate through a lateral-fastening structure.

FIG. 1 is a schematic view of a structure with the club head body and the striking face plate being combined through a lateral-fastening structure. The conventional golf club head includes a striking face plate 110 and a club head body 120. The striking face plate 110 is cup shaped, and at least one catching flange 111 is disposed near an inner side at an opening. A catching portion is disposed on an end surface of the club head body 120 facing the striking face plate 110, and at least one annular slot 121 is opened at a position of the catching portion corresponding to the catching flange 111. Then, after the catching flange 111 and the annular slot 121 are aligned with each other, the striking face plate 110 is pressed under an external force in order to engage the catching flange 111 with the annular slot 121, so that the striking face plate 110 is combined with the club head body 120 to form a club head through the lateral-fastening structure.

However, the above manner has inevitable disadvantages, that is, if shapes of the catching flange and the annular slot are poorly designed, if the design of the corresponding position is inaccurate, if the force is not uniformly applied on the striking face plate, or if the stress resistance of the fabrication material itself is relatively high, then the striking face plate and the club head body cannot be easily engaged together closely. A slit may be generated at the joint surface, so that the combined strength of the striking face plate and the club head body is quite limited. Furthermore, due to the external force, the striking face plate may fall off the club head body.

SUMMARY OF THE INVENTION

In order to solve the above problems, the present invention provides a golf club head, which is capable of easily, quickly and accurately combining the striking face plate and the body closely into a whole, effectively controlling the effective striking area of the striking face plate, easily performing the light-weighting or weighting block operating flow, and preventing a joint slit from generating at the joint surface between the striking face plate and the body, so as to improve the combined strength of the striking face plate and the body.

The present invention provides a golf club head. The golf club head includes a face plate and a body. The face plate has an annular fastening portion with at least one fastening groove mounted therearound. The body has a clamping portion including at least one annular block and at least one annular stopper. An accommodation slot is formed between the annular block and the annular stopper, and is used for accommodating the annular fastening portion. At least one flange is disposed on the top of the clamping portion. During the assembling process, the annular fastening portion corresponds to the accommodation slot, and the face plate is pressed under an external force and squeezed towards the body. At this time, the flange bears against the face plate, and the flange is pressed so that it is deformed towards the direction of the fastening groove, so as to form a catching portion for being engaged with the fastening groove. The annular block bears against the annular fastening portion, so as to help the annular fastening portion to be accurately accommodated into the accommodation slot and closely adhered to the accommodation slot.

In addition, when the flange is disposed on an end surface of the annular stopper facing the face plate, if the position of the annular stopper corresponds to an inner side of the annular fastening portion, the fastening groove is disposed on the inner side of the annular fastening portion corresponding to the position of the flange, and the annular block is disposed correspondingly on an outer side of the annular fastening portion. However, if the position of the annular stopper corresponds to the outer side of the annular fastening portion, the fastening groove is disposed on the outer side of the annular fastening portion corresponding to the position of the flange, and the annular block is disposed on the inner side of the annular fastening portion. Next, if the flanges are disposed on the end surfaces of both the annular block and the annular stopper facing the face plate, the fastening grooves are disposed on both the inner side and the outer side of the annular fastening portion. Furthermore, the cross section of the fastening groove is a trapezoid and with the opening facing the annular stopper, and the flange is disposed on the end surface of the annular stopper facing the face plate. Furthermore, the flange can be disposed around the clamping portion in a continuous manner or an equidistant or non-equidistant interrupted manner, and the fastening groove, corresponding to the flange, is mounted around the annular fastening portion in a continuous manner or an equidistant or non-equidistant interrupted manner. In addition, the fastening groove is a groove with a rectangle-shaped, arc-shaped, straight V-shaped, or trapezoid-shaped cross section, and the club head is one of an iron club head, a wood club head, or a putter head.

The following efficacies are achieved by the present invention. The striking surface can be randomly designed, and can extend to the outer side of the body to increase the effective striking area. Next, the striking face plate can be light-weighted by using a titanium alloy, which is helpful for the weighting process. Furthermore, it merely requires the processes of joining the striking face plate and the body, pressing the flange into the fastening groove, and performing a layout flattening operation, so the yield is is improved without any complex operating flow. Furthermore, the face plate and the body are closely joined together through making the annular block bear against the annular fastening portion, thereby preventing the joint slit from generating on the joint surface.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic structural view of a conventional golf club head;

FIG. 2A is a schematic structural view of a golf club head according to a first embodiment of the present invention;

FIG. 2B is a schematic structural view of the golf club head at pressing process according to the first embodiment of the present invention;

FIG. 2C is a combined schematic structural view of the golf club head according to the first embodiment of the present invention;

FIG. 3A is a schematic structural view of a golf club head according to a second embodiment of the present invention;

FIG. 3B is a combined structural schematic view of the golf club head according to the second embodiment of the present invention;

FIG. 4A is a schematic structural view of a golf club head according to a third embodiment of the present invention;

FIG. 4B is a combined schematic structural view of the golf club head according to the third embodiment of the present invention;

FIG. 5A is a schematic structural view of a golf club head according to a fourth embodiment of the present invention;

FIG. 5B is a combined schematic structural view of the golf club head according to the fourth embodiment of the present invention;

FIG. 6A is a schematic structural view of a golf club head according to a fifth embodiment of the present invention;

FIG. 6B is a combined schematic structural view of the golf club head according to the fifth embodiment of the present invention;

FIG. 7A is a schematic structural view of a golf club head according to a sixth embodiment of the present invention;

FIG. 7B is a schematic structural view of a golf club head at the pressing process according to the sixth embodiment of the present invention;

FIG. 7C is an enlarged schematic structural view of the golf club head at the pressing process according to the sixth embodiment of the present invention;

FIG. 7D is a combined schematic structural view of the golf club head according to the sixth embodiment of the present invention;

FIG. 8A is a schematic structural view of a golf club head according to a seventh embodiment of the present invention;

FIG. 8B is a combined schematic structural view of the golf club s head according to the seventh embodiment of the present invention;

FIG. 9A is a schematic structural view of a golf club head according to an eighth embodiment of the present invention;

FIG. 9B is a combined schematic structural view of the golf club head according to the eighth embodiment of the present invention;

FIG. 10A is a schematic structural view of a golf club head according to a ninth embodiment of the present invention;

FIG. 10B is a combined schematic structural view of the golf club head according to the ninth embodiment of the present invention;

FIG. 11A is a schematic structural view of a golf club head according to a tenth embodiment of the present invention;

FIG. 11B is a combined schematic structural view of the golf club head according to the tenth embodiment of the present invention;

FIG. 12A is a schematic structural view of a golf club head according to an eleventh embodiment of the present invention; and

FIG. 12B is a combined schematic structural view of the golf club head according to the eleventh embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

To make the objective, structural features, and function of the present invention more comprehensible, the relevant embodiments and detailed description of the drawings are described as follows.

FIGS. 2A to 2C are a schematic structural view, a schematic structural view at the pressing process, and a combined schematic structural view of a golf club head according to a first embodiment of the present invention respectively, which show the process of combining a face plate 210 with a body 220. The face plate 210 has an annular fastening portion 211, and a fastening groove 212. The fastening groove 212 with a rectangle-shaped cross section is mounted around an inner side of the annular fastening portion 211. The body 220 has a clamping portion 221 formed by an annular block 222 and an annular stopper 223. An accommodation slot 225 is formed between the annular block 222 and the annular stopper 223. An opening of the accommodation slot 225 corresponds to the annular fastening portion 211, and the annular stopper 223 comprises a flange 224 disposed on an end surface of the annular stopper 223 facing the face plate 210.

The annular fastening portion 211 and the accommodation slot 225 are made to align with each other, and the face plate 210 is pressed under an external force and squeezed towards the body 220. The annular fastening portion 211 is accurately placed into the accommodation slot 225. In this embodiment, the position of the annular block 222 corresponds to the outer side of the annular fastening portion 211, and the position of the annular stopper 223 corresponds to the inner side of the annular fastening portion 211. The flange 224 bears against the face plate 210, and the face plate 210 and the body 220 are continuously squeezed with each other in order to be gradually deformed towards the direction of the fastening groove 21, so as to form a catching portion 227 for being engaged with the fastening groove 212. However, the annular block 222 bears against the outer side of the annular fastening portion 211, which aims at preventing the annular fastening portion 211 from being deformed due to an excessively strong force generated when the face plate 210 and the body 220 are squeezed with each other. Therefore, the annular fastening portion 211 can be closely adhered to the inner side of the accommodation slot 225, so as to prevent slits from being generated at the joint surface between the face plate 210 and the body 220. Furthermore, if slight bumps or metal burrs are generated at the outer side part of the joint surface between the face plate and the body due to the mutual squeezing process therebetween, a polishing process or other similar surface processing operations can be used for finishing.

FIGS. 3A and 3B are a schematic structural view and a combined schematic structural view of a golf club head according to a second embodiment of the present invention respectively. In order to assure that the flange is deformed towards the direction of the fastening groove during squeezing, the flange is designed with a configuration having a lead angle, as shown by the trapezoid flange 226. When the face plate 210 and the body 220 are squeezed with each other, the trapezoid flange 226 firstly bears against the face plate 210 and is pressed by the squeezing force, and an inclined surface of the trapezoid flange 226 is relatively slowly pressed by the squeezing force, so the trapezoid flange 226 can only be deformed towards the fastening groove 212 to form a catching portion 227 for being engaged with the fastening groove 212.

FIGS. 4A and 4B are a schematic structural view and a combined schematic structural view of a golf club head according to a third embodiment of the present invention respectively. The fastening groove can be designed as a trapezoid-shaped fastening groove 213 with a trapezoid-shaped cross section, so that the trapezoid flange 226 can form a hook-shaped catching portion 227 once it is squeezed and deformed, thereby enhancing the engagement effect between the face plate 210 and the body 220. In addition, the fastening groove can be designed as grooves in different shapes, for example, with an inclined V-shaped, arc-shaped, or straight V-shaped cross section, depending upon different situations. Furthermore, the flange can be disposed around the clamping portion in a continuous manner or an equidistant or non-equidistant interrupted manner, and the fastening groove, corresponding to the flange, is mounted around the annular fastening portion in a continuous manner or an equidistant or non-equidistant interrupted manner.

FIGS. 5A and 5B are a schematic structural view and a combined schematic structural view of a fourth embodiment of the present invention respectively. In this embodiment, the position of the annular stopper 223 corresponds to the outer side of the annular fastening portion 211, and the position of the annular block 222 corresponds to the inner side of the annular fastening portion 211, so the fastening groove 212 is opened on the outer side of the annular fastening portion 211. The trapezoid flange 226 is disposed on the end surface of the annular stopper 223 facing the face plate 210. During the assembling process, the trapezoid-shaped flange 226 bears against the face plate 210 and is deformed towards the direction of the fastening groove 212, so as to form the catching portion 227 for being engaged with the fastening groove 212. At this time, the annular stopper 223 may generate slight bumps or metal burrs due to the squeezing process, and a polishing process or other similar surface processing operations can also be used for finishing. The annular fastening portion 211 bears against the annular block 222 to prevent the slits from being generated at the joint surface.

FIGS. 6A and 6B are a schematic structural view and a combined schematic structural view of a golf club head according to a fifth embodiment of the present invention respectively. The fastening grooves 212 are disposed on both the inner side and the outer side of the annular fastening portion 211 on the face plate 210. The flanges 224 are disposed on both the end surfaces of the annular block 222 and the annular stopper 223 facing the face plate 210. Therefore, when the face plate 210 and the body 220 are assembled, the flanges 224 are turned to become the catching portion 227 for being engaged with the fastening groove 212. In this embodiment, the combined strength of the face plate 210 and the body 220 is increased through the multi-engaging effects of the catching portion 227 and the fastening groove 212.

FIGS. 7A to 7D are a schematic structural view and a schematic flow chart of a sixth embodiment of the present invention respectively. The face plate 210 has a butting fastening portion 230 having a butting fastening groove 231 with a trapezoid-shaped cross section. The opening of the butting fastening groove 231 is relatively small, and the opening faces the body 220. The body 220 has a butting clamping portion 240 that includes an outer annular block 241, an inner annular block 242, and a central annular stopper 243. The central annular stopper 243 forms a butting accommodation slot 244 with the outer annular block 241 and the inner annular block 242 respectively.

During the assembling process, the butting fastening groove 231 corresponds to the central annular stopper 243 and accommodates the central annular stopper 243 therein. The central annular stopper 243 bears against the face plate 210 and they are squeezed with each other, so that the central annular stopper 243 is pressed by the squeezing force and deformed, and thus engages with the butting fastening groove 231. The butting accommodation slot 244 accommodates the protruding part of the butting fastening portion 230, and the outer annular block 241 and the inner annular block 242 bear against the outer side of the butting fastening portion 230, so as to prevent slits from being generated at the joint surface between the face plate 210 and the body 220.

FIGS. 8A and 8B are a schematic structural view and a combined schematic structural view of a golf club head according to a seventh embodiment of the present invention respectively, which show the process of combining the face plate 210 with the body 220. In this embodiment, the body 220 does not have the accommodation slot 225 mentioned in the above embodiments. The face plate 210 has the annular fastening portion 211. The annular fastening portion 211 includes a protrusion 214 and a fastening groove 212. The protrusion 214 is used to define the fastening groove 212, and the fastening groove 212 with a rectangle-shaped cross section is disposed on the outer side of the annular fastening portion 211. The body 220 has an annular stopper 223, and a flange 224 is disposed on the top of the annular stopper 223.

During the assembling process, the annular stopper 223 corresponds to the fastening groove 212, and the face plate 210 is pressed under an external force and squeezed towards the body 220. In this embodiment, the position of the annular stopper 223 corresponds to the outer side of the annular fastening portion 211, and the position of the fastening groove 212 corresponds to the outer side of the annular fastening portion 211. The flange 224 is disposed on the inner side of the annular stopper 223. The flange 224 bears against the face plate 210, and due to the continuous squeezing between the face plate 210 and the body 220, the flange 224 is gradually deformed towards the direction of the fastening groove 212, so as to form a catching portion 227 for being engaged with the fastening groove 212, and thus making the face plate 210 and the body 220 closely combined.

FIGS. 9A and 9B are a schematic structural view and a combined schematic structural view of a golf club head according to an eighth embodiment of the present invention respectively. The structure in this embodiment is similar to that of the seventh embodiment in that the body 220 does not have the accommodation slot 225. However, in this embodiment, the face plate 210 further includes an annular strip 215 disposed on the outer side of the annular fastening portion 211, and the distance between the annular strip 215 and the protrusion 214 is sufficiently long for accommodating the annular stopper 223. In addition, the fastening groove 212 is disposed on the outer side of the annular fastening portion 211, and the inner side of the annular fastening portion 211 has a step-like cross section.

During the assembling process, the annular stopper 223 corresponds to a corresponding position between the annular strip 215 and the protrusion 214, and the face plate 210 is pressed under an external force and squeezed towards the body 220. The flange 224 bears against the face plate 210 so that the flange 224 is deformed towards the direction of the fastening groove 212, so as to form the catching portion 227 for being engaged with the fastening groove 212. The annular strip 215 bears against the outer side of the annular stopper 223, so that the annular stopper 223 is accommodated between the annular strip 215 and the annular fastening portion 211, and thus the face plate 210 and the body 220 are closely combined.

FIGS. 10A and 10B are a schematic structural view and a combined schematic structural view of a golf club head according to a ninth embodiment of the present invention respectively. The similarity between this embodiment and the seventh embodiment is that the body 220 does not have the accommodation slot 225. However, in this embodiment, the annular fastening portion 211 of this embodiment is disposed on the periphery of the face plate 210, the annular stopper 223 is disposed correspondingly on the inner side of the annular fastening portion 211, the fastening groove 212 is disposed on the inner side of the annular fastening portion 211, and the flange 224 is disposed on the outer side of the annular stopper 223.

During the assembling process, the annular stopper 223 corresponds to the fastening groove 212, and the face plate 210 is pressed under an external force and squeezed towards the body 220. The flange 224 bears against the face plate 210, and due to the continuous squeezing between the face plate 210 and the body 220, the flange 224 is gradually deformed towards the direction of the fastening groove 212, so as to form a catching portion 227 for being engaged with the fastening groove 212, and thus the face plate 210 and the body 220 are closely combined.

FIGS. 11A and 11B are a schematic structural view and a combined schematic structural view of a golf club head according to a tenth embodiment of the present invention respectively. The structure of this embodiment is similar to that of the eighth embodiment, but in this embodiment, the annular strip 215 has an inclined bottom part 216 gradually inclined from the outer side edge of the annular strip 215 to the inner side edge of the annular strip 215, and the thickness of the outer side edge of the annular strip 215 is greater than that of the inner side edge of the annular strip 215. The inclined bottom part 216 is opposite a bearing surface 228 of the body 220, and the bearing surface 228 is a plane.

During the assembling process, the outer side edge of the inclined bottom part 216 firstly contacts the outer side edge of the bearing surface 228 of the body 220, and an external force is applied to press and thus deform the bearing surface 228 of the body 220, so that the inclined bottom part 216 of the annular strip 215 and the bearing surface 228 of the body 220 are closely adhered.

FIGS. 12A and 12B are a schematic structural view and a combined schematic structural view of a golf club head according to a eleventh embodiment of the present invention respectively. The structure of this embodiment is similar to that of the tenth embodiment, but in this embodiment, the annular strip 215 has a step-like bottom part 217 with a pressing block 218 disposed on the outer side edge thereof. The step-like bottom part 217 is opposite a bearing surface 228 of the body 220, and the bearing surface 228 is a plane.

During the assembling process, the pressing block 218 firstly contacts the outer side edge of the bearing surface 228 of the body 220, and an external force is applied to press the bearing surface 228 of the body 220 so that it is deformed, and the step-like bottom part 217 is also deformed accordingly, so that the step-like bottom part 217 of the annular strip 215 and the bearing surface 228 of the body 220 are closely adhered.

The face plate 210 can further include an annular strip disposed on the inner side of the annular fastening portion. In addition, besides the rectangle-shaped cross section mentioned in the above embodiment, the fastening groove 212 can also have a trapezoid-shaped, arc-shaped, straight V-shaped, or inclined V-shaped cross section.

While the embodiments of the present invention have been illustrated and described, various modifications and improvements can be made by those skilled in the art. The embodiments of the present invention are therefore described in an illustrative, but not restrictive, sense. It is intended that the present invention may not be limited to the particular forms as illustrated, and that all modifications which maintain the spirit and scope of the present invention are within the scope as defined in the appended claims. 

1. A golf club head, comprising: a face plate, having an annular fastening portion with at least one fastening groove mounted therearound; and a body, having a clamping portion, the clamping portion comprising at least one annular block and at least one annular stopper, an accommodation slot formed between the annular block and the annular stopper, and used for accommodating the annular fastening portion, and at least one flange disposed on the top of the clamping portion; wherein the annular fastening portion corresponds to the accommodation slot, the face plate is pressed under an external force and squeezed towards the body, the flange bears against the face plate and is squeezed towards the direction of the fastening groove, so as to be deformed to form a catching portion for being engaged with the fastening groove, and the annular block bears against the annular fastening portion, so that the annular fastening portion is placed into the accommodation slot and is adhered to the accommodation slot.
 2. The golf club head as claimed in claim 1, wherein the flange is disposed on an end surface of the annular stopper facing the face plate.
 3. The golf club head as claimed in claim 2, wherein a position of the annular block corresponds to an outer side of the annular fastening portion, a position of the annular stopper corresponds to an inner side of the annular fastening portion, and the fastening groove is disposed in the inner side of the annular fastening portion.
 4. The golf club head as claimed in claim 2, wherein the position of the annular block corresponds to the inner side of the annular fastening portion, the position of the annular stopper corresponds to the outer side of the annular fastening portion, and the fastening groove is disposed in the inner side of the annular fastening portion.
 5. The golf club head as claimed in claim 1, wherein the flanges are disposed on both end surfaces of the annular block and the annular stopper facing the face plate, and the fastening grooves are disposed on both the inner side and the outer side of the annular fastening portion corresponding to the position of the flanges.
 6. The golf club head as claimed in claim 1, wherein an opening of the fastening groove faces the annular stopper, a cross section of the fastening groove is a trapezoid, and the flange is disposed on the end surface of the annular stopper facing the face plate.
 7. The golf club head as claimed in claim 1, wherein the flange is disposed around the clamping portion in an equidistant or non-equidistant interrupted manner.
 8. The golf club head as claimed in claim 7, wherein the fastening groove is opened around the annular fastening portion in the equidistant or non-equidistant interrupted manner.
 9. The golf club head as claimed in claim 1, wherein the flange is disposed around the clamping portion in a continuous manner.
 10. The golf club head as claimed in claim 9, wherein the fastening groove is opened around the annular fastening portion in a continuous manner.
 11. The golf club head as claimed in claim 1, wherein the fastening groove is a groove with an inclined V-shaped cross section.
 12. The golf club head as claimed in claim 1, wherein the fastening groove is a groove with a rectangle-shaped cross section.
 13. The golf club head as claimed in claim 1, wherein the fastening groove is a groove with an arc-shaped cross section.
 14. The golf club head as claimed in claim 1, wherein the fastening groove is a groove with a straight V-shaped cross section.
 15. The golf club head as claimed in claim 1, wherein the fastening groove is a groove with a trapezoid-shaped cross section.
 16. A golf club head, comprising: a face plate, having an annular fastening portion with at least one fastening groove mounted therearound; and a body, having an annular stopper, wherein at least one flange is disposed on the top of the annular stopper; wherein the annular stopper corresponds to the fastening groove, the face plate is pressed under an external force and squeezed towards the body, and the flange bears against the face plate and is squeezed towards the direction of the fastening groove, so as to be deformed to form a catching portion for being engaged with the fastening groove.
 17. The golf club head as claimed in claim 16, wherein the annular fastening portion further comprises a protrusion for defining the fastening groove.
 18. The golf club head as claimed in claim 16, wherein a disposing position of the annular stopper corresponds to an inner side of the annular fastening portion, the fastening groove is disposed on the inner side of the annular fastening portion, and the flange is disposed on an outer side of the annular stopper.
 19. The golf club head as claimed in claim 16, wherein the position of the annular stopper corresponds to the outer side of the annular fastening portion, the fastening groove is disposed on the outer side of the annular fastening portion, and the flange is disposed on the inner side of the annular stopper.
 20. The golf club head as claimed in claim 16, wherein the fastening groove is disposed on one side of the annular fastening portion, and the other side of the annular fastening portion has a step-like cross section.
 21. The golf club head as claimed in claim 16, wherein the face plate further comprises at least one annular strip, and the position of the annular strip corresponds to the outer side of the annular fastening portion.
 22. The golf club head as claimed in claim 16, wherein the face plate firer comprises at least one annular strip, and the position of the annular strip corresponds to the inner side of the annular fastening portion.
 23. The golf club head as claimed in claim 16, wherein the fastening groove is a groove with an inclined V-shaped cross section.
 24. The golf club head as claimed in claim 16, wherein the fastening groove is a groove with a rectangle-shaped cross section.
 25. The golf club head as claimed in claim 16, wherein the fastening groove is a groove with an arc-shaped cross section.
 26. The golf club head as claimed in claim 16, wherein the fastening groove is a groove with a straight V-shaped cross section.
 27. The golf club head as claimed in claim 16, wherein the fastening groove is a groove with a trapezoid-shaped cross section.
 28. The golf club head as claimed in claim 21, wherein the annular strip has an inclined bottom part gradually inclined from the outer side edge to the inner side edge of the annular strip.
 29. The golf club head as claimed in claim 21, wherein the annular strip has a step-like bottom part with a pressing block disposed on the outer side edge thereof. 